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Biomedical subjects

H W Kim

Publications and source records attributed to H W Kim.

At least 127 records · Page 7Linked to original sources

Strain-specific serum antibody responses in infants undergoing primary infection with respiratory syncytial virus.

We sought to characterize the human respiratory syncytial virus (RSV) subgroup-specific antibody response to primary infection with RSV. RSV isolates from 43 infants and young children were typed as either subgroup A (Long strain-like) or B (18537 strain-like) based on reactivity with monoclonal antibodies. Acute-phase or preinfection and convalescent-phase sera were collected from the 43 subjects and tested in an enzyme-linked immunosorbent assay using purified F and G glycoproteins from RSV subgroups A and B and by neutralization assay against both subgroups of RSV. Twenty-six individuals had rises in titer of antibody to F glycoprotein, 27 to G glycoprotein, and 28 had rises in titer of neutralizing antibody. The antibody responses to homologous and heterologous F glycoproteins were not significantly different. In contrast, homologous vs. heterologous antibody responses to G glycoprotein were significantly different, with 7.3% relatedness between the G glycoproteins of subgroups A and B. Analysis of neutralizing antibody responses revealed 31% relatedness.

Antibodies, Monoclonal↗

Effects of hemoglobin perfusion on contractile function of the isolated ventricular septa.

Effects of three unmodified hemoglobin solutions on myocardial contractile function was evaluated using isolated perfused rabbit interventricular septa. The hemoglobin solutions tested were: a human hemoglobin solution (SFHS-A), a bovine hemoglobin prepared by a column chromatography (SFHS-B), and a bovine hemoglobin obtained by a ultrafiltration method (SFHS-C). Myocardial effects were assessed by comparing contractile parameters; developed tension (DT), resting tension (RT), and perfusion pressure (PP), measured before (control perfusion with Tyrode buffer) and during hemoglobin perfusion. Further, to examine the effects of hemoglobin solutions on myocardial contractility following a period of impaired flow, septal responses to a 10-minute period of ischemia (stopflow) were also studied. After a 10-minute perfusion with hemoglobin solution, SFHS-C increased DT to 124 +/- 12% (paired t-test, p less than 0.05) without causing a significant increase in RT or PP while SFHS-A and SFHS-B decreased DT to 96 +/- 20% (p greater than 0.05) and to 77 +/- 7% (p less than 0.05), respectively. A significant rise in PP (40-50% above baseline) was also noted with these solutions (p less than 0.05). Similarly, after a 30-minute reperfusion following a 10-minute ischemia, SFHS-C allowed significantly better percentage recovery (95 +/- 3%) than septa perfused with SFHS-A (81 +/- 2%) or SFHS-B (63 +/- 6%) (Student's t-test, p less than 0.05). These results indicate that hemoglobin solution, if properly prepared, does not seem to have acute deleterious effects on contractile function of the isolated heart.

Animals↗

Respiratory syncytial virus infections and intravenous gamma-globulins.

The respiratory syncytial virus (RSV) is a common cause of bronchiolitis and pneumonia in infants and young children. Throughout the world annual RSV epidemics result in numerous hospitalizations, substantial morbidity and some mortality. Until the recent introduction of ribavirin only supportive therapy has been available for treating these infections. The development of animal models of RSV infection and the observation that some lots of immunoglobulin prepared for intravenous administration contained substantial RSV-neutralization antibody titers, prompted a series of studies examining the safety and efficacy of immunoglobulin prepared for intravenous administration in the prophylaxis and treatment of RSV infections. This discussion will review our published, or soon to be published, studies on the use of Sandoglobulin for both immunoprophylaxis and immunotherapy of RSV infections in cotton rats. It will summarize studies utilizing both parenteral and topical (tracheal) Sandoglobulin therapy for RSV infections in owl monkeys. Finally the results of a small double blind trial of parenteral albumin or Sandoglobulin in the therapy of RSV bronchiolitis and/or pneumonia in hospitalized children will be reviewed. The data show that immunoprophylaxis and immunotherapy of RSV infections in laboratory animals was well-tolerated, was safe and induced highly significant reductions in RSV shedding from the lower respiratory tract. Further, immunotherapy of RSV infections in children was also well-tolerated, induced no short or long term evidence of toxicity or injury and caused significant improvements in oxygenation and reductions in RSV shed from the respiratory tract.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Lack of effects of calcium X calmodulin-dependent phosphorylation on Ca2+ release from cardiac sarcoplasmic reticulum.

Canine cardiac sarcoplasmic reticulum is phosphorylated by an endogenous calcium X calmodulin-dependent protein kinase and phosphorylation occurs mainly on a 27 kDa proteolipid, called phospholamban. To determine whether this phosphorylation has any effect on Ca2+ release, sarcoplasmic reticulum vesicles were phosphorylated by the calcium X calmodulin-dependent protein kinase, while non-phosphorylated vesicles were preincubated under identical conditions but in the absence of ATP to avoid phosphorylation. Both non-phosphorylated and phosphorylated vesicles were centrifuged to remove calmodulin, and subsequently used for Ca2+ release studies. Calcium loading was carried out either by the active calcium pump or by incubation with high (5 mM) calcium for longer periods. Phosphorylation of sarcoplasmic reticulum by calcium X calmodulin-dependent protein kinase had no appreciable effect on the initial rates of Ca2+ released from cardiac sarcoplasmic reticulum vesicles loaded under passive conditions and on the apparent 45Ca2+-40Ca2+ exchange from cardiac sarcoplasmic reticulum vesicles loaded under active conditions. Thus, it appears that calcium X calmodulin-dependent protein kinase mediated phosphorylation of cardiac sarcoplasmic reticulum is not involved in the regulation of Ca2+ release and 45Ca2+-40Ca2+ exchange.

Animals↗

Aerosolized ribavirin in the treatment of patients with respiratory syncytial virus disease.

Thirty children 1 to 33 months of age were enrolled in a study of aerosolized ribavirin therapy for respiratory syncytial virus lower respiratory tract illness. Twenty patients received ribavirin and 10 received placebo. There were no significant differences between the groups in chronologic or gestational age or in days of illness prior to admission. Among patients with pneumonia 17% of 6 placebo patients vs. 64% of 11 ribavirin patients had radiographic evidence that multiple lung lobes were affected (P = 0.06). Placebo patients received 42.5 to 94.7 hours (mean, 58.6) of aerosol therapy, whereas ribavirin patients received 36.3 to 95.6 hours (mean, 55.7). Seventy-seven percent of all study patients were discharged within 5 days of starting treatment. Severity of illness was evaluated daily using a scale of 0 (normal) to 4+ (most severe). Ribavirin patients initially had a mean severity score 0.5 higher than placebo patients. By Day 2, their rate of improvement was significantly greater than that of placebo patients (P = 0.001). By Day 5, 36% of ribavirin patients with rales showed improvement, whereas rales persisted in 100% of placebo patients. The rate of improvement of oxygen saturation from first to last day of treatment was statistically significant only for ribavirin patients (P = 0.02). On Day 3, 65% of ribavirin patients (13) vs. 50% (5) placebo patients shed 10(-0.5) 50% tissue culture infective dose virus per 0.2 ml of nasal wash. No side effects or toxicity were associated with aerosol therapy. A short course of ribavirin treatment (approximately 3 days) proved safe and beneficial.

Administration, Inhalation↗

Longitudinal study of rotavirus infection and gastroenteritis in families served by a pediatric medical practice: clinical and epidemiologic observations.

During 29 months of prospective longitudinal study of diarrhea in the home, human rotaviruses (HRVs) infected one or more members in 51% of 65 families, 35 of 126 children (28%) and 16 of 124 adults (13%). Within the 33 affected families, 57% of 62 children and 25% of 65 adults were infected. HRV gastroenteritis peaked at 40/100 person years at ages 12 to 23 months and decreased to 5 episodes/100 person years in adults. Among 25 children 0 through 36 months of age who had HRV infection, 88% were symptomatic. Of the 22 children with symptomatic HRV infection, 1 required hospitalization and 8 were seen by their physician for supportive care. HRVs were found in 12% of 216 stools obtained during gastrointestinal illness, but in only 0.2% of 1238 non-illness stools tested. HRV infections were noted as early as October and as late as April. Of 33 families who were studied for 2 seasons, at least 1 individual in each of 3 families experienced HRV infections in both years, but only one, an adult, shed virus and had symptoms in both seasons.

Adolescent↗

Intravenous immunoglobulin treatment of respiratory syncytial virus infections in infants and young children.

Respiratory syncytial virus (RSV)-infected cotton rats (Sigmadon hispidus) and owl monkeys (Aotus trivirgatus) showed significant reductions in RSV shedding from their respiratory tracts following parenteral therapy with human intravenous immunoglobulin (IVIG) containing high titers of RSV-neutralizing antibody. Because this therapy was well tolerated and appeared safe, a double-blind, placebo-controlled IVIG immunotherapy pilot study was performed on 35 hospitalized, RSV-infected infants and children. The treatment was well tolerated and resulted in significant reductions in nasal RSV shedding and in improvements in transcutaneous oximetry readings. However, the mean duration of hospitalization was not reduced by IVIG treatment. Followup to date has revealed no harmful effects resulting from immunotherapy of RSV infections. These studies appear to refute the hypothesis that passively acquired antibody may exacerbate RSV bronchiolitis or pneumonia in infants. Studies with larger numbers of seriously ill children will be required to determine if immunoglobulin G immunotherapy of RSV infections in infants is of clinical value.

Child↗

Environmental exposure of primary care personnel to ribavirin aerosol when supervising treatment of infants with respiratory syncytial virus infections.

The potential exposure to ribavirin aerosol in the environment was assessed in nurses caring for infants and children with severe lower respiratory tract infections due to respiratory syncytial virus. Ribavirin aerosol was administered via a ventilator, oxygen tent, or oxygen hood. Participants worked directly with infants receiving ribavirin for 20.0 to 35.0 h over a 3-day period. No toxic or adverse effects of ribavirin aerosol were observed in any of the 19 nurses studied, and ribavirin was not detected in erythrocytes, plasma, or urine collected after the potential exposure period.

Adult↗

Evaluation of a latex test for rotavirus detection.

A latex agglutination (LA) test (Slidex Rota-Kit; bioMérieux, Marcy-l'Etoile, France) was a rapid, easily used method for detecting rotavirus (RV) in pediatric fecal specimens. With 45 RV-positive and 50 RV-negative diarrhea specimens, the sensitivity of the LA test was 82%, and the specificity was 100%. Six other specimens produced indeterminate results. The frequency of positive LA tests appeared to be proportional to the concentration of virions in the stool.

Child, Preschool↗

Simultaneous infections with different enteric and respiratory tract viruses.

Infants and young children with rotavirus (RV) or visualized adenovirus in their stools were tested for the simultaneous presence of a respiratory viral pathogen in their upper respiratory tract. Overall, at least 10.7% of 484 study subjects had such dual infections, including 8.3% of 385 RV-positive gastroenteritis patients and 24.3% of 37 RV-positive respiratory disease patients. Respiratory syncytial virus was present in 34.1% of 41 dual infections with RV and at least 40% of the 12 to 15 dual infections with visualized fecal adenovirus. Other pathogens found in the respiratory tract of patients with RV or visualized fecal adenovirus infections included influenza viruses, adenoviruses, parainfluenza viruses, rhinoviruses, and a cytomegalovirus.

Adenoviridae Infections↗

Dissociation between serum neutralizing and glycoprotein antibody responses of infants and children who received inactivated respiratory syncytial virus vaccine.

The serum antibody response of infants and children immunized with Formalin-inactivated respiratory syncytial virus (RSV) vaccine 20 years ago was determined by using an enzyme-linked immunosorbent assay specific for the RSV fusion (F) and large (G) glycoproteins and a neutralization assay. Twenty-one young infants (2 to 6 months of age) developed a high titer of antibodies to the F glycoprotein but had a poor response to the G glycoprotein. Fifteen older individuals (7 to 40 months of age) developed titers of F and G antibodies comparable to those in children who were infected with RSV. However, both immunized infants and children developed a lower level of neutralizing antibodies than did individuals of comparable age with natural RSV infections. Thus, the treatment of RSV with Formalin appears to have altered the epitopes of the F or G glycoproteins or both that stimulate neutralizing antibodies, with the result that the immune response consisted largely of "nonfunctional" (i.e., nonneutralizing) antibodies. Subsequent natural infection of the vaccinees with wild-type RSV resulted in enhanced pulmonary disease. Despite this potentiation of illness, the infected vaccinees developed relatively poor G, F, and neutralizing antibody responses. Any or all of three factors may have contributed to the enhancement of disease in the RSV-infected vaccinees. First, nonfunctional antibodies induced by the inactivated RSV vaccine may have participated in a pulmonary Arthus reaction during RSV infection. Second, the poor antibody response of infants to the G glycoprotein present in the Formalin-inactivated vaccine may have been inadequate to provide effective resistance to subsequent wild-type virus infection. Third, the relatively reduced neutralizing antibody response of the infant vaccinees to wild-type RSV infection may have contributed to their enhanced disease by delaying the clearance of virus from their lungs.

Antibodies, Viral↗

Serum immunoglobulin G antibody subclass responses to respiratory syncytial virus F and G glycoproteins after primary infection.

Because the immunoglobulin G (IgG) response to carbohydrate antigens is typically from the IgG2 subclass and the IgG response to protein antigens is typically from the IgG1 and sometimes the IgG3 subclass, two respiratory syncytial virus glycoproteins, F and G, which differ substantially in the amount of glycosylation, were used as antigens in an enzyme-linked immunosorbent assay to determine IgG subclass responses in 20 infants and young children with naturally acquired respiratory syncytial virus infection. Both glycoproteins elicited primarily IgG1 and IgG3 responses, indicating that the protein moieties of the glycoproteins may be immunodominant in this age group.

Antigens, Viral↗